Electroprocessing apparatus



Nov. 5, 1968 J. RYERSON ET AL 3,409,531

BLECTROFROCESSING APPARATUS 4 Sheets-Sheet 1 Filed Feb. 16, 1965 ro i w 1 l 1 HM 3 O l FIGZ O M TWM mS E S RER Y W? M E R N NS m smo m M W M2 Nov. 5, 1968 J. N. RYERSON ET AL 3,409,531

ELECTROPROCESSING APPARATUS 4 Sheets-Sheet 2 Filed Feb. 16. 1965 m ul INVENTORS 1 AT T RNEYS JAMES N. RYERSON DAVID S. ACKERMAN ARNOLD E. KREAM b omm 5m QUE 57mg Nov. 5, 1968 J. N. RYERSON ET L 3,409,531

I ELECTROPROCESSING APPARATUS Filed Feb. 16, 1965 4 Sheets-Sheet 5 III.

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i, i lil i 296a INVENTORS JJA/Es A/ 16 6250 DAV/0 5. Jemima v 40/040 6 Kiev/w lam/w; Z ATTORNEYS Nov. 5, 1968 RYERSQN ET AL 3,409,531

ELECTROPROCESSING APPARATUS 4 Sheets-Sheet 4 Filed Feb. 16, 1965 S mu m MM AM V MEw me kT if Fa M 5 0 MMM #04 United States Patent 3,409,531 ELECTROPROCESSING APPARATUS James N. Ryerson, Oceanport, David S. Ackerman,

Linden, and Arnold E. Kream, Hillside, N.J., assignors to The Meaker Company, Nutley, N.J., a corporation of Illinois Continuation-impart of application Ser. No. 310,274,

Sept. 20, 1963. This application Feb. 16, 1965, Ser.

8 Claims. (Cl. 204-198) ABSTRACT OF THE DISCLOSURE In the illustrated embodiments precious metal plating is carried out by a loop series of tanks on a table, small electronic components being individually partially immersed so as to plate predetermined portions of the components. Multiple parts may be treated by quick disconnect fixtures with precise locating'surfaces. The entire machine may be sold as a complete package requiring a minimum of site preparation.

This is a continuation-in-part of our copending application Ser. No. 310,274 filed Sept. 20, 1963. This invention relates to a processing machine and particularly to a precision automatic plating apparatus for coating predetermined surface areas of a succession of work units with a precious metal or the like.

In the electrodeposition of precious metals such as gold it is evident that the amount of material deposited on each work unit should be controlled with great precision in order to avoid waste of the expensive plating material.

One commercial machine in accordance with the present invention is capable of plating 900 parts per hour and yet meets the critical requirements for precious metal plating in the electronics industry. The processing tanks of this machine are mounted on a table under a transparent canopy. The unit is supplied with its own hot air blow-off dryer. Water supply and drains for rinse tanks are pre-piped within the supporting frame for the table. Ventilation and direct current power units are installed as integral parts of the system. The system may thus be sold as a complete package requiring the minimum of site preparation and facilities.

It is therefore an important object of the present invention to provide automatic conveying apparatus providing for precise location of work units during travel through a precious metal plating solution or the like.

It is another object of the present invention to provide a novel automatic processing machine which may be sold substantially as a complete package requiring a minimum of site preparation and facilities.

Another object of the invention is to provide a work carrier providing precision adjustment of the work position for use in precision metal plating and the like.

Another object of the present invention is to provide a work carrier providing for plating of work units to any of a plurality of precisely controlled depths.

Still another object of the present invention is to provide an electroprocessing system in which a plurality of parts to be plated can be loaded onto a fixture in a precise position to cause each part to receive an equal amount of plating.

Yet another object of the present invention is to provide 3,409,531 Patented Nov. 5, 1968 ice a fixture which can be quickly and easily loaded of parts to be plated, and thereafter quickly and easily unloaded of such parts.

A still further object of the present invention is to provide an electroprocessing fixture for transistors or the like.

Other objects, features and advantages of the present invention will be apparent from the following detailed description taken in connection with the accompanying drawings, in which:

FIGURE 1 is a somewhat diagrammatic perspective view of a plating machine in accordance with the present invention;

FIGURE 2 is a somewhat diagrammatic fragmentary plan view of the apparatus of FIGURE 1;

FIGURE 3 is a somewhat diagrammatic vertical sectional view showing at the left work units travelling in a plating tank and at the right work units being transferred between successive tanks of the processing machine of FIGURE 1;

' FIGURE 4 is a vertical sectional view taken along the line 1VIV of FIGURE 3;

FIGURE 5 is a vertical sectional view taken along the line VV of FIGURE 3;

FIGURE 6 is a vertical sectional view taken along the line VI-VI of FIGURE 3;

FIGURE 7 is a vertical sectional view taken along the line VII-VII of FIGURE 3;

FIGURE 8 is a side elevational view of a work positioning gauge in accordance with the present invention;

FIGURE 9 is a top plan view of the work positioning gauge of FIGURE 8;

FIGURE 10 is a somewhat diagrammatic view of a single channel of a fixture which is used with the processing machine of FIGURE 1 and which channel is shown in a loading position to receive transistors or the like;

FIGURE 11 is a somewhat diagrammatic view of a complete fixture which comprises a plurality of channels as shown in FIGURE 10 and which channels are shown in a plating position;

FIGURE 12 is a detailed view of a pivotally connected carrier arm assembly which is used to carry the fixture of FIGURE 11 during the plating process;

FIGURE 13 is a vertical sectional view taken along line XIIIXIII of FIGURE 12;

FIGURE 14 is another embodiment of a fixture which can be used with the processing machine of FIGURE 1;

FIGURE 15 is still another embodiment of a fixture which can be used with the processing machine of FIG- URE 1; and

FIGURE 16 is a vertical sectional view taken along line XVIXVI of FIGURE 15;

FIGURE 1 represents a commercial embodiment of the present invention wherein the conveying apparatus such as represented in FIGURES 2 and 3 is associated with a series of processing tanks mounted on a table or platform 10 which is supported from the factory floor or other rigid horizontal surface by means of a frame 11. The tanks and conveyor apparatus are covered by means of a canopy 12 having a series of transparent windows such as indicated at 13 and 14. A hot air blower mechanism may be mounted as indicated at 16 within the frame 11 for discharging hot air into a space thereabove within the canopy 12 to provide for a circulation of hot air in and about the work units travelling toward a work unloading position, for example. The intake for the blower may be suitably filtered as required to prevent foreign matter from reaching the interior space of the canopy 12, and the interior space of the canopy may be vented by tub s 17. and 18. Water supply pipes such as and drains such as indicated at 21 for the rinse tanks are pre-piped integrally with the frame 11 as is the blower 16 and its ducts. Direct current power units such as indicated at 22 are installed as integral parts of the system. The machine may thus be sold as a complete package requiring the minimum of site preparation and facilities.

The particular machine illustrated is for precision precious metal plating of electronic components. The machine is capable of processing 900 parts per hour, and the work units are circulated by means of work carriers such as indicated at moving in a closed loop path within the canopy 12. Access to the carrier arms 30 for loading and unloading of work units may be provided at a section such as indicated at 32 of the canopy 12. The controls for the unit may be located at panels such as indicated at 33 and 34 adjacent the location 32.

Referring to FIGURE 2, the work carriers 30 are moved in the direction of arrow at one side of the machine such as the far side as viewed in FIGURE 1 and are moved in the opposite direction as indicated by arrow 41 at the other long side of the machine such as the near side as viewed in FIGURE 1. An endless chain is indicated at 44 having straight lengths thereof 44a and 44b at opposite sides of the center line of the machine and connected by semi-circular length portions at the opposite ends of the machine. Suitable sprocket wheels (not shown) may be located at opposite ends of the machine and receive the chain 44 thereabout, the sprocket wheels being rotatable on vertical axes.

As seen in FIGURE 2, each link of the chain may be joined with an adjacent link by means of pins such as 45 and 46. The pins 45 and 46 carry rollers such as indicated at 47 and 48 riding on respective chain roller guide rails indicated at 50 and 51. These rails 50 and 51 terminate adjacent the sprock t wheels at the opposite ends of the chain since the chain is guided by means of the teeth of the sprocket wheels at the ends of the chain path.

Referring to FIGURE 3, a conveyor mounting plate 55 may be supported by suitable frame members such as indicated at 56 and 57 which are rigidly connected with the frame 11. As seen in FIGURE 3, chain roller guide rails 50 and 51 may be supported from plate 55 by means of spacers or tubular configuration such as indicated at 59 and 60. A top plate 63 is supported from rails 50 and 51 by means of further spacers 64 and 65. Suitable fastening means such as bolts or the like may fasten plate 63 with plate 55 and extend through the interiors of spacers such as 59 and 64, and and 65.

At each carrier position along the chain 44, the chain is provided with angle brackets such as indicated at secured to a carrier arm attachment bracket such as indicated at 71. The attachment brackets 71 are guided by means of lower rails 75 and 76 and upper rails 77 and 78 so as to maintain the pivot shafts such as indicated at 80 and 81 carried by the brackets 71 at a precise level relative to the table 10. The lower attachment rails 75 and 76 are mounted on the plate 55 by means of spacers such as indicated at 85 and 86 receiving suitable fastening means through the interior thereof, and the upper attachment guide rails 77 and 78 are suspended from the plate 63 by means of spacers such as indicated at 87 and 88 with suitable fastening means extending through the interior of the spacers (not shown). The plate 63 thus serves to suspend the attachment guide rails 77 and 78 which together with the guide rails 75 and 76 and the roller guide rails 50 and 51 serve to guide the carrier arm attachment members 71 along the opposite straight portions of the chain path.

Since in the illustrated embodiment the carrier arm assemblies are identical except as hereafter described, corresponding reference numerals will be applied to certain similar parts of both of the carrier arm assemblies shown in FIGURE 3. Certain parts of the right hand carrier arm assembly have been given corresponding primed reference numerals to indicate an alternative construction which may be employed. The carrier arms 30 and 30' shown in FIGURE 3 are secured to the attachment brackets 71 by means of pivot members 91 and 91'. As seen in FIG- URE 2, the attachment brackets 71 are provided with journal flanges 71a and 71b receiving the shafts such as indicated at 80 which mount the pivot members 91. The shaft 80 is provided with a bushing 101, FIGURE 3, for insulating the pivot member 91 from the shaft 80, and the side flanges 71a and 71b are provided with insulation as indicated at 102 and 103, FIGURE 2, for electrically isolating the pivot member 91.

Each of the carrier arm pivot members 91 is slotted at its outer end to provide end portions 91a and 91b receiving the vertical leg portion 30a of one of the carrier arms 30 as seen in FIGURE 4. Fastening means are indicated at 95 and 96 in FIGURES 3 and 4 for securing the carrier arms with the pivot members 91.

'Each of the carrier arm pivot members 91 is provided with a roller which is freely rotatable on a cylindrical portion of the member 91 and is retained in position on the member by means of a collar such as indicated at 111. Cam track sections are indicated at 112 and 113 for raising the carrier arms at desired locations along the path of the conveyor chain. The cam track sections may be mounted by means of suitable plates such as indicated at 115 which are supported at a fixed position relative to the frame members such as 56 and 57.

As seen in FIGURE 3, the processing apparatus may comprise a series of processing tanks such as indicated at 121 and 122 supported on the table 10 by means of suitable spacers such as indicated at 123 and 124.

By way of example, the tank 121 may contain a solution of a precious metal to be plated on work units such as indicated at 126. The level of the plating solution is precisely determined by means of an overflow passage such as indicated at 128 leading to a drain reservoir 129 and a drain pipe 130. Simply by way of example, a rectangular screen anode has been indicated at 132 extending along the bottom of the tank 121.

As seen in FIGURE 3, the outer free ends of carrier arms 30 are provided with collector shoes such as indicated at riding on a horizontal carrier guide rail 141. The guide rail 141 is supported at a precisely determined adjustable horizontal level by means of a bracket 142 which is insulated from the rail by means of a bushing 143 and washer 144. The rail 141 preferably is connected to the electrical supply so as to serve as a cathode connection with the carrier arms as the carrier arms move across the plating tanks such as indicated at 121. Insulated sections of rail aligned with the rail 141 may support the carrier arms at other portions of the machine particularly where the level of the work pieces such as 126 is to be precisely determined. At other portions of the machine where the positioning of the work is not critical, cam sections such as indicated at 112 may be provided with lower horizontal sections of a height to suitably support the carrier arms. of course, at the plating tanks, the lower portions of the cam tracks such as indicated at 112a do not determine the horizontal level of the carriers, the carriers resting on the cathode rails such as indicated at 141.

The right hand side of FIGURE 3 shows a cam track section 113 which serves to pivot the carrier arms upwardly about the axes of shafts such as indicated at 81 so as to clear the work of the end wall 122a of the tank 122.

By way of a preferred example of an adjustment mechanism for the rail sections such as indicated at 141,

a block 160 has been indicated secured to a plate 161 and to bracket 142 by means of screws such as 158. The bracket 142 and an angle bracket 162 may have vertically elongated slots therein receiving clamping screws such as indicated at 163. The screws 158 may be located on opposite sides of angle bracket 162 so as to receive nuts such as 159 seated against the right hand face of bracket 142 as viewed in FIGURE 3. The angle bracket 162 may be secured to the table 10. A clamping nut member 165 may threadedly receive the screws such as 163. The block 160 may have a threaded aperture receiving a screw 170 which at its lower end engages the top surface of table 10. A locking nut is indicated at 171 for fixing the screw 170 in a desired adjusted position. Thus, to adjust the height of rail 141, screws such as 163 are loosened and lock nut 171 is loosened and screw 170 turned to provide the desired height of the rail 141. The bracket 142 is then clamped to the angle 162 by means of the screws such as 163 and screw 170 is locked in its adjusted position by means of nut 171.

By way of illustration, the leading end 121a of tank 121 has been indicated in FIGURE 2 and the beginning of the cathode rail 141 has been indicated at 141a. These parts are arranged so that as the carrier arms 30 pivot downwardly into operative position to the solution within tank 121, the free ends of the arms rest upon the cathode rail 141. The cam rail section 112 may include an upper portion 112b laterally aligned with the end wall 121a of tank 121 so as to maintain the carrier arms in the upwardly pivoted condition indicated at the right in FIGURE 3. The lower level portion 112a of the cam track may terminate as indicated in FIGURE 2, since this portion of the cam track does not perform a supporting function at the plating tank 121. It will be understood, however, that there is a downwardly inclined section connecting portions 112b and 112a of the cam track 112 and that there is a similar upward-1y inclined portion in advance of end wall 121a of tank 121 unles the work carrier arms are already in an upwardly pivoted condition.

Referring to FIGURES 3 and 7, it will be observed that the carrier arms 30 have housings 202 secured thereto by means of screws 203 and 204 and that the housings have rectangular apertures receiving corresponding cross section portions of workpiece locating plates 210. Specifically, the housing 202 receives a constant cross section portion 210a of plate 210, FIGURE 8, which has a series of notches 211-214 along a lower edge face 21% thereof. The housing 202 includes a casing 215 having a compression spring 217 urging a ball detent 218 against the lower edge 21% so as to be seated selectively in one of the notches 211-214 to fix the lateral position of the plate 210 with respect to the carrier arm 30.

The carrier arms have similar housings 221 and 222. For illustrative purposes, the housing 221 on the right hand carrier as viewed in FIGURE 3 has been shown as having a workpiece 150 located by edge face 231 of gauge 210. Exemplary details have been indicated in FIGURE 5. Housing 222 associated with the left hand carrier arm 30 in FIGURE 3 has been shown as having the work-piece 126 associated therewith. By way of example, the workpieces 126 and 150 may be of different length and may require a different depth of immersion in the plating solution of plating tank 121.

Referring to FIGURE 8, it will be observed that the positioning plate or gauge 210 has an upper edge face 230 and lower edge faces 231-234 and 241-244 at successively different vertical distances from the edge face 230. FIGURE 5 shows the edge face 231 of the work positioning gauge 210 determining the depth of plating for the workpiece 150 while edge 244 of the gauge 210 is shown as locating workpiece 126 in FIGURE 6. Any suitable means may be provided for retaining the workpieces 126 and 150 with their upper edge faces in abutting pressure contact with the lower edge faces 231 and 244. By way of example, ball detents have been indicated for this purpose. Referring to FIGURE 5, a ball 250 is urged by means of a compression spring 251 against the upper sloping surface such as indicated at 252a of a notch 252. In the illustrated structure, the ball 250 is not seated at the bottom of the notch 252 so that there is a component of force tending to press the upper edge face of workpiece 150 against the edge face 231 of plate 210. The casing 254 for the spring 251 is, of course, secured in a suitable aperture in the housing 221.

The structure for positioning workpiece 126 in FIG- URE 6 may comprise a ball 260, a compression spring 261, a recess or notch 262 and a casing 263 secured to the housing 222.

As seen in FIGURE 8, the spacing between the successive notohes 211-214 corresponds to the spacing between the successive edge faces such as 231-234 and 241-244 so that when the positioning plate 210' is shifted laterally to align a different one of the notches 211-214 with the detent 218, FIGURE 7, a corresponding different edge face of the series 231-234 will be located in housing 221 and a corresponding different edge face of the series 241-244 will be positioned in the housing 222. Lateral adjustment of the positioning plate 210 is facilitated by a turned end portion 210c best seen in FIGURE 9 which may be conveniently grasped by the fingers of the operator.

By way of example, the gauge or positioning plate 210 may have its lower edge faces such as 231-234 and 241-244 located with an accuracy of plus or minus .001 inch with respect to the upper edge 230. The carrier arm and gauge may have a thickness of A; inch, for example. The carrier arms may be of extruded aluminum and of T cross section. The work holding housings 221 and 222 may have a sliding fit with respect to the sides of gauge 210 and may have inch diameter apertures at the lower ends thereof receiving the upper cylindrical ends of the workpieces such as .126 and 150 with a tight fit.

Simply by way of example, the chain may have successive pins such as indicated at 45 and 46 spaced one inch apart with the total chain length being 240 inches. The chain may be suitably driven either continuously or intermittently through the medium of one of the sprocket wheels at the ends of the chain loop.

The basic machine may, of course, incorporate a selectively operable by-pass of any of the processing stations; and other features such as air agitation, solution recirculation and the like may be provided.

The carrier rollers may ride on a horizontal elongated cam track section disposed at the level of cam track portion 11% in FIGURE 3 for maintaining the arms in the upper position adjacent the loading and unloading section of the machine such as indicated at 32 in FIGURE 1. The height of tracks 112 and 113 may be adjustable by means of clamping screws such as 270 and 271 which extend through vertically elongated slots 115a and 115b of mounting plate 115 and threadedly engage fixed block 272.

By way of example, the frame 11 may support the table 10 at a height of approximately three feet above the factory floor or other rigid supporting surface.

Shown in FIGURE 10 is a single channel mounting bracket 280 which is expressly designed to receive transistors or the like which are to be electroplated. The mounting channel 280 is formed by a U-shaped member 281 which is of insulating material such as plastic. Secured to the extreme ends of the leg portions of the U- shaped bracket 281 are a pair of fluted channel assemblies 284 and 285, which preferably each comprise an elongated notched strip 286 and a thin elongated cover strip 287. The strip 287v is secured or bonded to the notched strip 286 in such a manner that a flute 288 is provided by the notched strip 286 and the strip 287. The fluted channel 285 is constructed in substantially the same manner as the fluted channel 284 to provide a flute 289.

The fiuted channels 284 and 285 are secured to the U- shaped mounting bracket 281 in such a manner as to provide the flutes 288 and 289 in parallel relation with each other, and also, the cover strips 287 are in spaced parallel relation to provide an opening 291 to receive the heads of transistors such as indicated by 293. Flutes 288 and 289 and the opening 291 form an indexing slot which extends the entire length of the mounting bracket 280 to receive a plurality of transistor heads as shown in FIGURE 10. It can be seen therefore, that the transistors are loaded into the indexing slot of the mounting bracket 280 one after another in serial fashion -until the mounting bracket 280 is completely filled.

Slidably carried within the U-shaped member 281 is a brush assembly 295 which consists of a brush head 296, a current lacing strip 297, and a multitude of small diameter wires 298 which are preferably of stainless steel to form the bristles of the brush 295. When the mounting bracket 280 is in the loading position, as shown in FIG- URE 10, the brush 295 will fall to the bottom of the U- shaped channel to prevent interference between the bristles 298 and the electrical leads 300-302 of the transistors 293. The leads 300-302 of transistors 293 are shown as being of the long flexible type; however, the transistor 293 may have leads which are short and rigid such as those found on power transistors.

FIGURE 11 shows a plurality of U-shaped mounting brackets 280 secured to a mounting plate 305 to form a fixture 304 capable of carrying a large number of transistors during the electroplating process. Also secured to the mounting plate 305 of the fixture 304 is a support 306 which is secured to an end portion of a carrier arm assembly 307. The fixture 304 is shown in the plating position with the heads of the transistors facing downward and with the bristles 298 of the brushes 295 in contacting relation with the transistor leads 300-302. It will be noticed in FIGURE 11 that the transistor leads are assumed to be of the short rigid type as mentioned hereinabove; this type of lead may allow the brushes 295 to fall substantially to the bottom of the mounting bracket 280.

All the mounting channels 280 are substantially constructed in the same manner and therefore only one mounting channel has been selected to show the manner by which the brush assembly 295 is slidably retained in the U-shaped channel. The brush head 296 has extended portions 296a and 296b which extend beyond the respective ends of the U-shaped mounting channel 280. A retainer 309, which has a central aperture shaped in correspondence to the cross section of the end portion of the brush head, is secured to the brush assembly 295 for movement therewith. A similar retainer is provided at the end portion 2961: thereby maintaining the brush assembly 295 longitudinally within the U-shaped mounting channel 280 and in a horizontal orientation.

A plug-in contact strip 310 is secured to the mounting plate 305 in such a manner as to receive the current carrying leads 312 each of which is connected to the copper lacing strip 297 of an associated brush assembly 295. As shown in FIGURE 11, each of the current carrying leads 312 is plugged into or otherwise detachably connected to the contact strip 310.

The plurality of mounting channels 280 must be maintained in a substantially horizontal position over a plating solution 315 so that each of the transistor heads 293 is submerged an equal depth in the plating solution 315.

FIGURE 12 shows an alternate embodiment of a carrier arm assembly which can be used to maintain the mounting channels 280 in a horizontal position over the plating fluid 315 in place of the arrangement of FIGURE 3. Secured to the attachment bracket 71 in FIGURE 12 is a U-shaped mounting bracket 320 which is arranged to receive a pivot member 321. The pivot member is preferably of electrically substantially non-conductive insulating material. A pin 323 is provided to pivotally connect the pivot member 321 to the bracket 320. Secured to the pivot member 321 is a rod 325 which serves to detachably receive the support 306 of FIGURE 11, and to provide a current conductor for th electroplating process. Rotatably mounted on the rod 325 is the roller which, as mentioned hereinabove, serves to engage the cam track 112 to raise and lower the carrier arm assembly 307 as required. The bracket 320 moves on a rail 326 which is supported by spacers such as 327. A second rail 330 is supported from the frame 56 by means of support members such as 331, 332 and 333 which are fastened together in a suitable manner and secured to the frame 56. The rail 330 provides an electrical contact means whereby electrical current required for the plating process is transmitted from the fixed rail 330 to the moving rod 325 by means of a contact cam 335. The support member 333 is preferably of electrical insulating material to prevent electric current from passing through the frame 56.

As shown in FIGURE 13, the contact cam 335 is provided with an eccentric bore 335a to receive the current carrying rod 325. The cam 335 is maintained in a fixed position on the rod 325 by means of a set screw 337. As the cam 335 and rod 325 move in the direction of the arrows 338, the cam will make continuous electrical contact with the rail 330 during predetermined portions of the electroplating process. If it is desired to adjust the horizontal position of the carrier arm 307, the cam 335 is loosened on the rod 325 and rotated thereabout to either raise or lower the carrier arm assembly about the pivot pin 323 to obtain the carrier arm assembly 307 in a substantially horizontal position. In this manner, the mounting plate 305 and mounting channels 280, of FIGURE 11, can be adjusted to a horizontal position over the plating fluid 315.

Shown in FIGURE 14 is another fixture arrangement 339 whereby a plurality of parts 340 can be secured to the end of the carrier arm assembly 307. A hub 341 is secured to an adapter bushing 342 by means of a set screw 343 and a in 344. The bushing 342 is provided with a tapped hole 345 to receive a set screw 346 which is provided to secure the bushing 342 to the rod 325. In this manner, the bushing 342 can be slidably adjusted to any desired position and then secured in place by the set screw 346. A rack 347 is secured to the hub 341 by means of a screw 349. The fixture 339 is placed on the end of the rod 325 by sliding the hub 341 onto the bushing 342 so that the pin 344 is received by an indexing slot 341a which serves to maintain the fixture 339 in a substantially vertical position over the plating solution 315. The hub 341 is then secured to the bushing 342 by the set screw 343. The rack 347 is provided with a plurality of male plug members 350355. The male plug members 350-355 are typically shown by the plug 350 which consists of an extended resilient portion 350a and a shoulder or stop portion 35011. In this instance, the work to be plated is of tubular form and is placed onto the plugs 350-355 in such a manner that the top edge 340a of the piece to be plated comes in contact with the stop member 35011 of the plug 350, thereby maintaining the parts 340 at a fixed distance from the rack 347 to maintain all the parts 340 in the plating solution 315 to an equal depth.

Shown in FIGURE 15 is still another fixture arrangement whereby a plurality of parts 360 can be secured to the end of the carrier arm assembly 307 during the plating process. A hub 361 is secured to an adapter bushing 362 by means of a set screw 363 and pin 364. Th bushing 362 is secured to the rod 325 by means of a set screw 365. A rack 367 is secured to the hub 361 by means of screws 368. Secured to the rack 367 is a plurality of retainers such as indicated at 370-374. The retainers 370-374 are substantially similar and consist of a threaded portion such as 370a. The retainer 370 is secured to the rack 367 by means of a nut 375. An inverted U-shaped spring clip 377 is secured between the rack 367 and the retainer 370 and provides clip means whereby the parts 360 can be secured between the retainer 370 and the spring clip 377 during the plating process. Thus the parts 360 can be quickly and easily detachably connected to the rack 367. The parts 360 are partially submerged in the plating solution 315 during a portion of their travel through the processing machine as in the preceding embodiments.

Shown in FIGURE 16 is an end section view taken along the lines XVI-XVI of FIGURE 15. FIGURE 16 specifically shows the retainer 370 and spring clip 377 secured within a channel 367a of the rack 367. The retainer 370 may also have a nut 378 for purposes of adjusting the retainer 370 vertically up and down on the rack 367. In FIGURE 15 the cathode current for the parts 360 is provided by the current pickup rail 330, through current cam 335, rod 325, bushing 362, hub 361, rack 367, and retainer 370. The cathode current for the tubular parts 340, FIGURE 14, is provided in substantially the same manner.

Summary of operation In placing the machine in operation, work units such as indicated at 126 in FIGURE 3 are positioned on the carrier arms 30 with the upper ends of the workpieces abutting respective edge faces such as indicated at 244 in FIGURES 6 and 8 of the work positioning gauge 210. The gauge 210 has its upper surface 230 engaging an undersurface of the carrier arm 30 so that the gauge 210 may be shifted laterally to position workpieces at different levels with respect to the carrier arm. Thus, inFIGURE and at the right in FIGURE 3, a workpiece 150 is shown positioned against the surface 231 of a gauge 210 which is in a different lateral position than the gauge 210 shown at the left in FIGURE 3.

The workpieces may be loaded with the carrier arms in an upper position such as shown at the right in FIG- URE 3. At the plating tanks such as indicated at 121 in FIGURE 3, elevator cam tracks 112 serve to raise the work units over the ends such as 121a of the plating tanks and then to immerse the work to the desired precisely controlled depth in the plating solution. Cathode rail sections such as indicated at 141 precisely determine the level of the carrier arms 30 as the carrier arms move longitudinally along the length of the plating tanks. The pivot shafts such as indicated at 80 at the left in FIG- URE 3 for the arms 30 are also precisely horizontally positioned by means of rails 50, 75 and 77. The carrier chain 44 is provided with rollers such as indicated at 47 riding on the straight rail sections 50 and 51 shown in cross section in FIGURE 3. The carrier arms do not rest on the cam track section 112a while in the plating tanks, but are supported by the rigidly fixed outboard cathode rail sections such as indicated at 141 so as to contribute to accurate locating of the workpieces in the plating solution.

If it is desired to adjust the carrier arms for a different workpiece length and plating depth, for example, the gauge plates such as 210 are grasped at the portion 2100 thereof, FIGURE 9, and moved laterally relative to the carrier arms 30 until a ball detent 28, FIGURE 7, is engaged in the appropriate notch 211-214, FIGURE 8. The corresponding positioning edge faces of the series 231-234 and 241-244 will then register with the work holding housings such as indicated at 221 and 222 in FIGURE 3 to provide the desired depth of plating for the new length of workpieces.

Utilizing a machine as illustrated and described herein, plating depth on the work units may be held precisely to a predetermined value with a tolerance of only plus or minus .005 inch.

In place of a positive connection between pivot members 91 and the carrier arm 30, any suitable quickly detachable coupling between these parts may be utilized, for example a friction fit or a sliding fit or either fit together with a suitable latch or detent such as indicated for parts 126 and 222 (including detent 260) in FIG- URE 6. This will facilitate automatic pre-loading of the carrier arms with work units prior to connection of the carrier arms with the conveyor parts 91, 70 and 44. In this case the work unit might be delivered directly from a machine tool which performs a machine operation on the work unit into a work magazine corresponding to carrier arm 30 but detachably engageable with the conveyor part 91 as above described.

The circles 95' and 96' at the right in FIGURE 3 represent suitable detent means such as indicated at 260, 263 in FIGURE 7 engaging in notches similar to that shown at 262 in carrier arm 30 to detachably retain the carrier arm with conveyor part 91. The parts 30 and 91 may have a sliding fit such as illustrated in FIGURE 4 (but with screws 95 and 96 omitted). The end wall of the slot in part 91 is indicated at 280 and the corresponding end wall of the slot bifurcating part 91' is indicated at 280. The carrier arm or magazine part 30' is detachably held by detents 95', 96' with its end abutting flatwise with the end wall 280' of conveyor part 91'.

FIGURE 3 at the right also illustrated a coupling consisting of a friction fit between parts 30' and 91' where 95', 96' are omitted or considered as unused apertures in part 91'.

Should it be desired to utilize the electroplating apparatus of FIGURE 1 for plating transistor heads or the like, it is desirable to use the fixture assembly shown in FIGURE 11. The fixture of FIGURE 11 may be removed from the carrier arm 307 and loaded at a loading station remote from the electroplating apparatus of FIG- URE 1. During the loading operation of transistors onto the mounting channels 280, the entire fixture 304 is inverted so that all of the brush assemblies 295 located Within the mounting channels 280 will fall substantially to the bottom of the channel as shown in FIGURE 10. The transistor heads 293 are then inserted into the indexing slot 291, and thereafter may be held in the indexing slot 291 by suitable retainer means located at the opposite ends of the slot. After the transistors have been loaded onto the fixture, the fixture is mounted onto the carrier arm assembly 307 so that the transistors are in a downward position as shown in FIGURE 11. This will cause the brush assembly 295 in each of the mounting channels 280 to fall toward the transistors thereby causing the wire bristles 298 to engage the transistor leads 300-302, one of which is connected to the transistor head 293 to provide a current path required for the plating process. It can be seen that with the fixture shown in FIGURE 11, the head portions of a multitude of transistors can be electroplated to an exact depth.

When a fixture such as that shown in FIGURE 14 is utilized with the electroplating apparatus of FIGURE 1, the fixture 339 can be removed from the carrier arm assembly 307 by loosening the set screw 343 and sliding the hub 341 and rack 347 off of the bushing 342, whereby the fixture can be removed to a loading area remote from the plating apparatus of FIGURE 1. The workpieces shown in FIGURE 14 are of tubular form and are connected to the fixture by means of male plugs 350- 355, each having a resilient body portion such as 350a. Each plug 350 355 is provided with a shoulder 350b, which is preferably a taper, to serve as a stop for the upper edge 340a of the workpieces 340. After the workpieces 340 have been mounted on the fixture 339, the fixture can be connected to the carrier arm assembly 307 and the hub 341 secured in place on the bushing 342 by the set screw 343. The indexing pin 344 is received by the slot 341a to insure that the fixture 339 is maintained in a substantially vertical position over the plating solution 315.

Should it be desired to plate workpieces having a shape similar to that shown in FIGURES 15 and 16, the fixture shown therein proves advantageous. As shown in FIG- URE 15, the workpieces 360 are held in place by a spring clip 377 which is resiliently biased against a retainer 370. The workpieces 360 are inserted between the spring clip 377 and retainer 370 and are held in place thereby during the electroplating process. It will be understood that the fixtures shown in FIGURES 14 and are extremely easy to load and unload, and therefore, the workpieces can be connected to the fixtures either at a station remote from the electroplating apparatus of FIG- URE 1 or at the electroplating apparatus.

It is important that the fixtures shown in FIGURES 11, 14 and 15 are maintained in a substantially horizontal position over the plating fluid 315 during the electroplating process. The horizontal position of these fixtures is controlled by the relationship of the cam 335 on the rod 325, shown in FIGURE 12. The pivot pin 323 serves as a fixed point about which the carrier arm assembly 307 can rotate above and below the horizontal plane. As shown in FIGURE 13, by merely loosening the set screw 337 and rotating the current cam 335 on the rod 325 the carrier arm assembly 307 can be adjusted to a subtantially horizontal position.

Of course a given processing machine may employ only one type of carrier arm assembly and only one type of fixture throughout. The channels 284 and 285 and the U-shaped member 281 are of electrical insulation material. Also, the bristles 298 may have a finite space between each wire forming the bristles and these wires may be laterally flexible to allow the leads 300302 of the transistors to mesh or intermingle with the bristles 298 to provide for electrical contact between an extended length portion of each lead and a plurality of laterally contacting bristles 298.

It will be apparent that many modifications and variations may be effected without departing from the scope of the novel concepts of th present invention.

By way of example only and not of limitation, the following modifications and variations and additional details are given.

In FIGURE 10, the wires 298 of electrically conductive material may have a lesser diameter and length than the leads 300-302. The wires 298 may have a space therebetween less than the diameter of the leads 300-302 and such that the wires 298 will be deflected slightly as the brush assembly 295 moves into engagement with the leads. The weight of the brush and its momentum (when the fixture 304 is returned from the orientation shown in FIGURE 10 to that shown in FIGURE 11) may be such as to insure that the leads 300302 will penetrate a substantial distance into the brush, the leads 300302 maintaining a substantially vertical orientation by virtue of the stiffness thereof. The wires 298 may have a stiffness which is not greater than and preferably less than the stiffness of the leads 300302.

In FIGURE 11, where stiffer and shorter leads are present as compared to leads 300302, the wires 298 may be longer than the leads, but otherwise may have the characteristics relative to the shorter leads corresponding to those given in the preceding paragraph with respect to leads 300302.

The bracket shown at 306 in FIGURE 11 may be considered to be a diagrammatic representation of the parts 341, 342, 343, 344, 345 and 346 of FIGURE 14, and the foregoing parts of FIGURE 14 are hereby specifically disclosed as being substituted for the bracket 306 in FIG- URE 11. Thus in assembling fixture 304 on th carrier arm after loading thereof as indicated in FIGURE 10, the hub 341 is slid onto the adapter sleeve 342 which has been previously fixed to rod 325, FIGURE 11, by means of set screw 346 with its locating pin 344 (which is secured to sleeve 342) in a precisely vertical orientation. The plate 305 is, of course, suitably secured to the hub member 341 by screws or the like. In the illustrated embodiment the set screw 343 is seated in an annular groove 342a centrally of sleeve 342 so as to locate the fixture 304 in a desired location axially of rod 325, although the use of a spring urged detent associated with screw 343 such as Spring urged ball 250, FIGURE 5, associated with screw or press fit casing 254 is hereby specifically disclosed with respect to the bracket means 306 of FIGURE 11. In such an embodiment, the ball would snap into groove 342a as hub 341 is slid onto sleeve 342 to securely locate the fixture 304 relative to arm 325, FIGURES 11, 12 and 13.

In each of the embodiments herein the screw 343 or 363 may house a spring urged ball as indicated at 250 in FIGURE 5, so that the fixtures can he slid onto sleeve 342 or 362 and will be automatically located thereon by means of such spring urged ball engaging in groove 342a or 362a.

By way of specific exemplary detail the sloping side walls of groove 342a or 362a may define an included angle therebetween of 120. The set screw 343 or 363 may have a central bore from the lower end of which projects a pin slidable in the bore. The pin may have a compression spring in the bor urging the pin outwardly. The maximum projection of the pin from the bore may be limited by a stop within the bore acting on a shoulder on the pin so that the pin will be cammed inwardly by the bevel end face 342]; or 36212 of sleeve 342 or 362. The wall 342b or 362b may define an angle of 30 relative to an axial direction, th same angle as the walls of groove 342a or groove 362a. Thus if the pin could only extend into the axial opening through sleeve 341 or 361 a distance of 40 mils, the depth of groove 342a or 362a being about 36 mils, then the bevel face 342b or 3621; might extend mils in the radial direction (1 mil=.001 inch). If th maximum width of groove 342a or 362a were .125 inch, the detent pin might have a diameter at its lower end of inch with a rounded lower end exactly as indicated at 343a in FIGURE 14 and 363a in FIG- URE 15. Thus, the showings of FIGURES 14 and 15 equally well represent a set screw 343 or 363 with an integral rounded tip end 343a or 363a, and a screw casing 343 or 363 having a hollow interior receiving the upper end of a spring urged detent pin 343a or 363a. The bevel face 342b or 362b may have an axial dimension of inch for the other dimensions just given, for example.

In FIGURES l5 and 16, the U-shaped springs 377 may each have an aperture in the bight portion 377a thereof which receives the screw thread portion 370a The nut 378 then serves to clamp the bight portion 377a against member 367. The free end 3771: of each spring 377 may be curved away from the associated member such as 371 so that the free end edge thereof will be spaced from the associated member a distance greater than the thickness of a workpiece prior to engagement of the workpiece therewith. By this construction the workpiece may be slid against the active leg of the U-shaped spring to wedge the leg away from the adjacent surface of the member. Thus the workpiece can be assembled on the fixture quickly without any necessity for manually grasping the legs of the U-shaped spring to retract the same from engagement with the associated members prior to moving the workpieces under the active legs of the springs.

It will be apparent that certain of the broad concepts of this invention are applicable to a straight line processing machine where the load and unload ends of the machine are at opposite ends of a straight line work carrier path. Further certain broad features relating to the work mounting fixtures of this invention are applicable to work carrier arms which are not pivotally mounted at one end. In general it is the intent that the appended claims be construed to cover all those modifications and variations which will become obvious to those skilled in the art after study of the present specification, as well as to cover improvements herein such as are built upon one or more of the novel concepts hereof and fall within the scope of one or more of the appended claims.

The following is a table illustrating by way of example, application of terms 1n the claims to exemplary parts in the drawings.

Term in Claims Exemplary Part No. Exemplary Figure No.

Conveyor part 321 12 Work carrier 325.... 10 Work mounting means- 280 10 Socket In part 221--. 5 Detent means 250 5 Horizontal guides 284, 285- Grooves .l 288, 289- 10 Resilient plugs 350355 14 7 Spring c1ips. 377 15 Guideway Defined by parts 284, 285..-- 10 The term friction fit is used herein to denote a location fit where sufficient lateral pressure is present between the mating parts to retain the parts in assembly during operation of the machine while accommodating repeated disassembly of the parts.

The term sliding fit between parts without any positive connection therebetween is used to cover a fit that is looser than a location fit together with an impositive retaining means such as the detent means 250 of FIGURE 5 or detent means at 363a in FIGURE 15.

We claim as our invention:

1. In a processing machine comprising means defining a series of processing stations, a conveyor disposed for movement along a path past the series of processing stations, conveyor parts coupled at said conveyor at intervals therealong for movement along said path, and work carriers coupled to said conveyor parts for movement by said conveyor through said series of processing stations, the improvement characterized by:

said conveyor parts having means for providing a quickly detachable connection with said work carries for conjoint movement of the work carriers with the conveyor parts along said path and for accommodating quick removal of the work carriers with treated work units therein from said conveyor parts for unloading of the-treated work units from said work carriers at a location separate from said machine, and said work carriers each having a plurality of work locations at a common level and each having Work mounting means for engaging the upper ends of a plurality of work units at said work locations to mount said work units for immersion as a group to a precisely controlled common depth in a treatment bath while the mounting means is located above said bath,

said work mounting means comprising horizontal guides spaced apart a distance to receive therebetween a series of work units and having horizontally extending opposed grooves therein lying in a common horizontal plane for slidably receiving flanges of the work units to support the series of work units at respective work locations along said guides and at a precise common level with the lower ends of the work units terminating below said guides for immersion in a treatment bath while the guides are above said bath.

2. In a processing machine comprising means defining a series of processing stations, a conveyor disposed for movement along a path past the series of processing stations, conveyor parts coupled to said conveyor at intervals threalong for movement along said path, and work carriers coupled to said conveyor parts for movement by said conveyor through said series of processing stations, the improvement characterized by:

said conveyor parts having means for providing a quickly detachable connection with said work carriers for conjoint movement of the work carriers with the conveyor parts along said path and for accommodating quick removal of the work carriers with treated work units thereon from said conveyor parts for unloading of the treated work units from said work carriers at a location separate from said machine,

and said work carriers each having a plurality of work locations at a common level and each having Work mounting means for engaging the upper ends 5 of a plurality of work units at said work locations to mount said work units for immersion as a group to a precisely controlled common depth in a treatment bath while the mounting means is located above said bath,

said work mounting means comprising a series of resilient plugs for engaging and retaining upper hollow ends of a series of work units at said work locations to precisely position the lower ends of the work units (for immersion to a predetermined depth in a treatment bath.

3. In a processing machine comprising means defining a series of processing stations, a conveyor disposed for movement along a path past the series of processing stations, conveyor parts coupled to said conveyor at intervals therealong for movement along said path, and work carriers coupled to said conveyor parts for movement by said conveyor through said series of processing stations, the improvement characterized by:

(a) said conveyor parts having means for providing a quickly detachable connection with said work carriers for conjoint movement of the work carriers with the conveyor parts along said path and for accommodating quick removal of the work carriers with treated work units thereon from said conveyor parts for unloading of the treated work units from said work carriers at a location separate from said machine, and said work carriers each having a plurality of work locations at a common level and each having work mounting means for engaging the upper ends of a plurality of work units at said work locations to mount said Work units for immersion as a group to a precisely controlled common depth in a treatment bath while the mounting means is located above said bath,

(b) said work mounting means comprising a series of downwardly opening spring clips each having a vertically extended fixed surface for engaging fiatwise with one side of a work unit and having deflecti-ble spring means urged toward said fixed surface for pressing a work unit t-hereagainst and frictionally holding the work unit, and a horizontally disposed locating surface for abutting the upper ends of a series of work units for retaining the units at a precise common level.

4. An electroplating machine for electroplating of precious metal onto work unit surfaces comprising:

(a) means defining a precious metal plating station,

(b) a conveyor disposed for movement along a horizontal path parallel to the precious metal plating station,

(c) work carriers coupled to said conveyor at intervals therealong for movement therewith,

(d) fixture means secured to said work carriers for carrying a plurality of work units, said fixture means including an elongated U-shaped channel member having mounting means formed at the extremity of the legs of the U-shaped channel member for receiving a series of work units to be electroplated, r

(e) contactor means for electrical connection with each of said fixture means for slid-ably carried in said U-shaped channel member thereof for sliding out of contact with the work units supported thereby during loading and unloading of the U-shaped channel memher and for sliding into contact with the work units during the electroplating process, and

(f) means engageable with said work carriers at said precious metal plating station for making electrical contact with the work units associated with said work carriers through said fixture means and said contactor means of said work carriers.

3,409,531 15 16 5. A work supporting fixture for a processing machine (c) said contactor means being adapted to engage eleccomprising: trical leads extending from the work units and com- (a) a channel member having a horizontally extending prising a brush element having a multiplicity of wires guideway for slidably receiving a series of work units extending toward said guideway, and having a vertically elongated channel extending (d) said wires having a stiffness less than the stiffness upwardly from said guideway in an operative orientaof the leads of the work units and a spacing so as tion of the channel member, and to receive the leads in intermeshing, laterally con- (b) contactor means vertically reciprocably mounted tacting relation therewith.

in said vertically elongated channel and movable to 8. A work supporting fixture for a processing machine a position remote from said guideway and out of comprising: contact with the work units in said guideway when (a) a plurality of channel assemblies each having a the channel member is shifted from its operative orientation to a loading orientation in which the channel member is inverted relative to its operative orientation, and movable to a position adjacent said vertically extending channel and having a work receiving means at the lower end of each of said channels with respect to an operative orientation of the channel assemblies for receiving a series of work units, (b) contactor means movably carried in each of said channels for making contact with the work units in guideway and in electrical contact with work units in said guideway when the channel member is shifted from its loading orientation to its operative orientation. the associated work receiving means when said chan- 6. A work supporting fixture for a processing machine nel is in the operative orientation and for moving comprising: out of contact with the work units when the channel assemblies are in an inverted orientation,

(c) circuit means connected to said contactor means to deliver current to said contactor means when the channel assemblies are in the operative orientation,

(d) mounting means mounting said channel assemblies (b) contactor means vertically reciprocably mounted with said work receiving means of said channel asin said vertically elongated channel and movable to semblies disposed substantially in a common plane, a position remote from said guideway and out of and contact with the work units in said guideway when (e) means secured to said mounting means to detachthe channel member is shifted from its operative ably connect the fixture to the processing machine. orientation to a loading orientation in which the channel member is inverted relative to its operative orientation, and movable to a position adjacent said guideway and in electrical contact with work units in said (a) a channel member having a horizontally extending guideway for slidably receiving a series of work units and having a vertically elongated channel extending upwardly from said guideway in an operative 25 orientation of the channel member, and

References Cited UNITED STATES PATENTS guideway when the channel member is shifted from fi f its loading orientation to its operative orientation, 1759171 5/1930 g 5""1] (c) said contactor means being adapted to engage elec- 1808809 6/1931 erg e a 204 297 trical leads extending from the work units and com- 1868320 7/1932 2O4 20 prisinga brush element having a multiplicity of wires 19S0096 3/1934 g g 7 i tom"! f 1 985 988 1/1935 Han%10n 204 203 coniprisggf supportlng xture or a processlng machlne Daw (a) a channel member having a horizontally extendl gg 5 1 ing guideway for slidably receiving a series of work 2214262 9/1940 2 17 units and having a vertically elongated channel ex- 2475'434 7/1949 14-37 tending upwardly from said guideway in an operative 9 O1- 4 orientation of the channel member a 2482269 9/1949 Gnmes 134160 2 721839 10/1955 T 1 204 27s (b) contactor means vertically reciprocably mounted ay or in said vertican Shepard et a1. y elongated channel and movable to a 2,861,936 11/1958 Colasanto 204l99 postlon remote from said guldeway and out of 3 035 999 5/1962 Sh I contact with the work units in said guideway when 3257308 6/1966 C aron at a 2o4297 the channel member is shifted from its operative 1733608 10/1929 Kottom 2041-497 orientation to a loading orientationin which the chan- 3254004 5/1966 2g g Z nel member 1s inverted relative to 1ts operatrve orien- 3:276:986 10/1966 Swistun tation, and movable to at position adjacent said guideway and in electrical contact with work units in said guideway when the channel member is shifted from its loading orientation to its operative orientation,

HOWARD S. WILLIAMS, Primary Examiner.

W. VAN SISE, Assistant Examiner. 

